Study design should go beyond answering a single question of Outcome
Editor –The paper by Holland etal. [1] highlights our current trials
design obsession of measuring an arbitrary outcome instead of
understanding the cause of such outcome through rigorous design aimed at
unravelling both the cause and effect of an intervention.
Clearly , the authors assumed a sound hypothesis –Polypharmacy is a
cause of drug adverse effects and interactions which has been shown to
increase hospitalisation. It follows that an intervention that is likely
to reduce this effect is likely to reduce hospital admissions. A much more
informative study, however, would have been to look at the outcome of
hospitalisation as well as its causes in both groups. An even better study
design would shed a light on the specifics of intervention. It is relevant
in this study to know the causes of admissions in each group. It is also
valid to ask what are the interventions by the pharmacist in the
intervention group that could have explained increased admission rates.
Neither of these important issues is mentioned in the paper which could
have been easily collected from patients’ admission data.
The unexpected negative outcome of the study made every one eager to know
the possible causes of this unexpected result.
If we to turn the fundamental conclusion of this study around and
assume that the study had shown a positive outcome with significantly
fewer admissions in the intervention group .The result would have been
accepted and used as evidence to promote new community pharmacist role in
order to avoid hospital admission ,without necessarily understanding how
the result is being achieved.
In research, it looks neat to attempt to answer one specific question
at time, which allows easier statistics calculations.This ,however ,
should not stop us from addressing the important issue of understanding
how the outcome is reached. This can be achieved by having an open mind to
the hypothesis under study and allow the study design to go beyond
answering a single question.
Refrences:
1.Does home-based medication review keep older people out of hospital? The
HOMER randomised controlled trial
Richard Holland, Elizabeth Lenaghan, Ian Harvey, Richard Smith, Lee
Shepstone, Alistair Lipp, Maria Christou, David Evans, Christopher Hand.
BMJ 2005;330:293, doi:10.1136/bmj.38338.674583.AE
Competing interests:
None declared
Competing interests:
No competing interests
09 February 2005
Abdullah Mohammed
Clinical Research Fellow
The Cardiothoracic unit,Northern General Hospital,Sheffield ,UK
Editor –The paper by Holland etal. [1] highlights our current trials
design obsession of measuring an arbitrary outcome instead of
understanding the cause of such outcome through rigorous design aimed at
unravelling both the cause and effect of an intervention.
Clearly , the authors assumed a sound hypothesis –Polypharmacy is a
cause of drug adverse effects and interactions which has been shown to
increase hospitalisation. It follows that an intervention that is likely
to reduce this effect is likely to reduce hospital admissions. A much more
informative study, however, would have been to look at the outcome of
hospitalisation as well as its causes in both groups. An even better study
design would shed a light on the specifics of intervention. It is relevant
in this study to know the causes of admissions in each group. It is also
valid to ask what are the interventions by the pharmacist in the
intervention group that could have explained increased admission rates.
Neither of these important issues is mentioned in the paper which could
have been easily collected from patients’ admission data.
The unexpected negative outcome of the study made every one eager to know
the possible causes of this unexpected result.
If we to turn the fundamental conclusion of this study around and
assume that the study had shown a positive outcome with significantly
fewer admissions in the intervention group .The result would have been
accepted and used as evidence to promote new community pharmacist role in
order to avoid hospital admission ,without necessarily understanding how
the result is being achieved.
In research, it looks neat to attempt to answer one specific question
at time, which allows easier statistics calculations.This ,however ,
should not stop us from addressing the important issue of understanding
how the outcome is reached. This can be achieved by having an open mind to
the hypothesis under study and allow the study design to go beyond
answering a single question.
Refrences:
1.Does home-based medication review keep older people out of hospital? The
HOMER randomised controlled trial
Richard Holland, Elizabeth Lenaghan, Ian Harvey, Richard Smith, Lee
Shepstone, Alistair Lipp, Maria Christou, David Evans, Christopher Hand.
BMJ 2005;330:293, doi:10.1136/bmj.38338.674583.AE
Competing interests:
None declared
Competing interests: No competing interests